the federal democratic republic of ethiopia ministry of

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The Federal Democratic Republic of Ethiopia

Ministry of Water, Irrigation and Energy

Community Led Accelerated WASH in

Ethiopia (COWASH)

Climate and Environmental Risk Screening

for COWASH Project

Regional Level Training of Trainers (ToT)

Manual

September 2015

Addis Ababa, Ethiopia

i

List of Acronyms

BGR Benishangul Gumuz Region

BoA Bureau of Agriculture

CMP Community Managed Project

COWASH community-Led Accelerated WASH

CR-WSP Climate Resilient Water Safety Plan

DEM Digital Elevation Method

EIA Environmental Impact Assessment

FTAT Federal Technical Assistant Team

NRM Natural Resource Management

O&M Operation and Maintenance

ODI Oversea development Institute

SNNPR Southern Nation's Nationalities People Region

ToT Training of Trainers

WASH Water Supply, Sanitation and Hygiene

WASHCO WASH Committee

WUA Water User Association

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Table of Content

Content page

List of Acronyms ........................................................................................................................................... i

Table of Content ........................................................................................................................................... ii

List of Figures ............................................................................................................................................... v

List of Tables ................................................................................................................................................ v

Section 1: Introduction (1hr)......................................................................................................................... 1

1.1. Overview of the ToT Manual............................................................................................................. 1

1.2. Who Use the ToT Manual .................................................................................................................. 1

1.3. Objective of the ToT Manual ............................................................................................................. 2

1.4. Outcome of the ToT Manual .............................................................................................................. 2

1.5. Structure of the ToT Manual .............................................................................................................. 3

Section 2: Climate Change Risk on WASH .................................................................................................. 5

Activity 2.1: Questioning participants (10 minutes) ................................................................................. 5

Activity 2.2: Power point presentation (30 minutes) ................................................................................ 5

2.1.Climate Change Risk on WASH ......................................................................................................... 5

2.2. Risk screening approaches ................................................................................................................. 9

Section 3: Understanding Water Availability – Tapping Existing Knowledge (Step 1) ............................ 10

Activity 3.1: Questioning Participants (10 minutes) ............................................................................... 10

Activity 3.2: Power Point Presentation (1hr & 10 minutes) ................................................................... 10

3.1. Understanding Local Geology (Step 1.1) ........................................................................................ 11

3.2. Understanding Source Behavior (Step 1.2) ...................................................................................... 16

3.3. Measuring the Yield of Existing Sources (step 1.3) ........................................................................ 17

Activity 3.4: Group Exercise (1hr & 20 minutes) ................................................................................... 18

Activity 3.3: Group presentations (40 minutes) ...................................................................................... 19

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Activity 3.4: General Discussion (20 minutes) ....................................................................................... 19

Section 4: Ensuring Sustainability - Estimating Supply and Demand (Step 2) .......................................... 20


Activity 4.2: Power Point Presentation (3hrs & 20 minutes) .................................................................. 21

4.1. Selecting sites – rules of thumb (Step 2.1) ....................................................................................... 21

4.2. Estimating demand (Step 2.2) .......................................................................................................... 24

4.3. Estimating the Required Catchment Size (wells) or yield (springs) - (Step 2.3) ............................. 25

Activity 4.4: Group Exercise (3hrs) ........................................................................................................ 31

Activity 4.5: Group presentations (1hr & 10 minutes) ........................................................................... 32


Section 5: Protecting Sites and Sources – Hazard Assessment and Mitigation (Step 3) ............................ 33


Activity 5.2: Power Point Presentation (1hr & 50 minutes) ................................................................... 34

5.1 Assessing direct hazards near a water point (Step 3.1) ..................................................................... 35

5.2. Assessing Indirect Environmental Hazards in the Wider Catchment (step 3.2) .............................. 39

5.3 Developing a Catchment Protection Plan (Step 3.3) ......................................................................... 43

Activity 5.3: Group Exercise (1hr& 30 minutes) .................................................................................... 45

Activity 5.4: Group presentations (40 minutes) ...................................................................................... 45


Section 6: Record Keeping ......................................................................................................................... 46


Activity 6.2: Power Point Presentation (40 minutes) .............................................................................. 46


Field Exercise (1day) .................................................................................................................................. 48

Reference .................................................................................................................................................... 50

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Annex 1: A field guidance sheet that can help the user identify rocks and their water resource potential . 51

Annex 2: Groundwater potential of major African hydro-geological environments .................................. 55

v

List of Figures

Fig. 3.1. Hydro-geological field notes plotted on a geological base map................................14

Fig. 3.2. Preliminary groundwater development plan..............................................................15

Fig. 4.1. Estimating the slope to avoid rapid drainage.............................................................22

Fig. 4.2. Scoping the best sites for a water point – the influence of drainage.........................22

Fig. 4.3. Width and Length of a catchment to calculate the size of a catchment....................28

Fig. 4.4. Catchment sizing for different rainfall, recharge and demand scenarios..................30

Fig. 5.1. Integrating environmental risk assessment in water point sitting.............................34

Fig. 5.2. Environmental hazards that might affect a water source..........................................35

Fig. 5.3. Picture showing active and deep gully......................................................................36

Fig. 5.4. Landslips/landslides...................................................................................................38

Fig. 5.5. Topographic base map showing areas of environmnetal degradation and initial

identification of causes............................................................................................................40

Fig. 5.6. Similar base map including major areas of environmental degradation and initial

identifications of causes...........................................................................................................41

Fig. 5.7. Base map showing measures to address catchment degradation..............................44

List of Tables

Table 1.1. Proposed Trainees who are to participate on the regional ToT.................................2

Table 2.1. Climate change impacts on WASH facilities and adaptation measures...................6

Table 3.1. Source type, functionality and access.....................................................................17

Table 3.2. Source problems and their causes............................................................................17

Table 3.3. Yield of existing water source.................................................................................18

Table 4.1. Importance of topography to avoid rapid drainage.................................................21

Table 4.2. Minimum Distances from Sources of Pollution......................................................23

Table 4.3. Estimating water needs............................................................................................24

Table 4.4. Estimating the catchment size and spring yield needed to meet demand...............27

Table 5.1. Assessing the risk posed by gullies to water points................................................36

Table 5.2. Examples of degradation features and possible reasons.........................................42

Table 5.3. Assessing the severity of degradation features.......................................................42

Table 5.4. Possible corrective measures for main degradation features..................................43

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Section 1: Introduction (1hr)

1.1. Overview of the ToT Manual

This manual is prepared based on the climate and environmental screening guideline prepared by

Overseas Development Institute (ODI). The training manual addresses the resource sustainability

mainly the water resource and environmental and climate risk elements to the water scheme

posed by flooding, land degradation, and climate change. The aim is to show how participants

from the WASH implementing organizations, working in partnership with communities, can

integrate these concerns into rural water supply planning and implementation activities.

The focus of this manual is on groundwater-based, community-managed wells and springs in

rural areas as these systems are potentially most vulnerable to climate change impacts. Systems

that depend on shallow groundwater from wells and springs are generally more vulnerable to

changes in rainfall (and therefore groundwater recharge) and demand than those exploiting

bigger groundwater storage. The activities proposed in this ToT manual are most useful where

water points are developed which access shallow groundwater, such as hand-dug wells, shallow

boreholes equipped with hand pumps and springs. This manual does not address:

• Formal Environmental Impact Assessments (EIAs), which should be carried out routinely

where deeper drilled boreholes are planned.

• Water quality assessment or sanitary surveys, which typically form part of a CR-Water

Safety Plan (CR-WSP).

1.2. Who Use the ToT Manual

It is proposed to train about 34 experts from FTAT, experts from regional water bureaus (Hydro-

geologists, and water engineers ); one NRM expert from BoA; and staffs from regional support

unit working on site selection (Hydro-geologist) and capacity building experts. These target

groups are selected because they are responsible for cascading the training to Woreda level

training. In Amhara region there are Zonal COWASH advisors that are proposed to be part of the

training so that they can support regional experts during Woreda training and follow up activities

during site selection. Hence, zonal advisors with hydrogeology/geology background from Amhar

region may participate on the ToT. Thus, the manual is used for all these target groups and

Woreda and zone WASH sector experts who are involved in rural water supply planning,

implementation and monitoring activities. Details of the regional ToT participants are presented

in table 1.1 below.

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Table 1.1. Proposed Trainees who are to participate on the regional ToT

Region/Federal Regional Participants Zonal

Advisors

Woreda

Advisors

Total

Regional Water, Mine and Energy

Bureau, BoA

Regional

Support Unit

(RSU)

FTAT 5

Oromia 3* 2 - - 5

Amhara 3* 2 3 - 8

SNNPR 3* 2 - 5

Tigray 3* 3 - - 6

BGR 3* 2 - - 5

Total 15 11 3 2 34

*(one hydro-geologist and one water resource engineer, and one NRM expert from BoA)

1.3. Objective of the ToT Manual

The main objective of the manual on the climate and environmental risk screening is to provide

the basic knowledge and skill on climate and environmental risk screening for regional

COWASH sector experts and zone and Woreda COWASH advisors. It will also provide the

required skills and tools for the trainees to cascade the training themselves to zone and Woreda

COWASH sector experts who are doing the actual work of climate and environmental risk

screening. The manual helps the regional WASH sector experts to effectively deliver the

required knowledge and skill on environmental and climate risks screening for Zone and Woreda

COWASH sector experts to enable them better plan, identify risks and take measures to

prevent/mitigate or effectively respond to environmental and climate risks.

It is also important that these new skills and knowledge on the climate and environmental risk

screening are internalized within the trainees for effective environmental assessment and climate

risk screening of COWASH project and that trainees have the knowledge and skills to work

closely with Zonal and Woreda WASH sector offices to adapt the ToT Manual.

1.4. Outcome of the ToT Manual

After the successful completion of this manual:

Trainees will be acquainted with the basic knowledge of climate change impacts on the

WASH facilities mainly on shallow groundwater abstraction technologies like spring

development and HDWs, and the adaptation measures for the impacts;

The capacity of trainees on the knowledge and skill on basic concepts of environmental

assessment and climate risk screening will be enhanced;

Trainees will understand how to identify and manage environmental and climate risks on

the COWASH project;

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The trainees will be provided with the knowledge, skills, and tools/methodologies to

cascade the training to Zone and Woreda experts in an understandable manner to people

who don’t have detailed background knowledge and skill of these issues.

1.5. Structure of the ToT Manual

This manual is organized in five sections.

Section 1: Introduction. This section give general overview of the ToT manual, the target groups,

the objective, and outcomes of the ToT, and the structure of the manual.

Section 2: Climate Change Risks on WASH - This section brief the main climate change impacts

on WASH and the corresponding adaptation strategies to reduce/minimize the risks.

Section 3: (Understanding Water Availability – Tapping Existing Knowledge) - this section

focuses on the importance of collecting existing information such as geology of the area,

performance of existing water sources, and yield of the different water sources; and how to do it.

The section also describes the factors that are likely to influence the availability and

sustainability (and quality) of water for a village or group of households. This is the first step

(step 1) in environmental assessment and climate risk screening in rural water supply planning

and implementation.

Section 4: (Ensuring Sustainability - Estimating Supply and Demand). The second step in

environmental assessment and climate risk screening is discussed in this section. This section

focuses on describing how to estimate the supply and demand of water so as to identify potential

sites for a well or spring that can provide water, at the required yield, on a continuous basis for

domestic needs.

Section 5: (Protecting Sites and Sources – Hazard Assessment and Mitigation). The main focus

of this section is assessment and management of environmental and climate risks posed to water

sources. This is the main section in this ToT manual in assessing the environmental and climate

risks to the rural water supply projects, and identifying the feasible mitigation measures for those

identified risks.

To make the ToT practical and attractive, a variety of training methods are used in each of the

training sections. Trainers should take care to avoid lengthy lectures or large group discussions,

always remembering that each individual learns in a different way. Trainers should try to use as

many of the following training methods as the length of the training session allows:

Lectures by the trainers (using PowerPoint presentations, overhead projectors),

Group discussions,

Group exercises, and activity questions,

Practical exercises in the field,

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Presentations by participants after group exercises, and field exercise

Check in and reflection session of the previous training day at the beginning of each day.

For the field visit activity, site will be selected and confirmed ahead of the training.

Trainees assessment and evaluation

At the beginning of the ToT, trainees will be assessed/evaluated on their knowledge and skills on the

subject matter to be covered by the ToT manual. At the end of the ToT, participants will be

assessed/evaluated on the knowledge and skill on the subject matters covered by the ToT. The

assessment/evaluation method is by preparing questionnaire to be filled by the trainees.

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Section 2: Climate Change Risk on WASH

Overview of the section: This section will introduce trainees on the impacts of climate change on

WASH facilities, and the adaptation strategies to reduce/minimize the impacts by climate change

on the WASH facilities especially on low technology rural water supply facilities mainly

protected springs, HDWs and shallow wells.

Activity 2.1: Questioning participants (10 minutes)

Before fully getting into this section, the trainer uses this activity to build anticipation for the

content and to gauge how much the trainees knows about the impacts of climate change on the

WASH facilities, and the adaptation strategies to minimize/reduce the impacts. Start the

discussion by asking participants a few simple questions about the impact of climate change on

WASH facilities and adaptation strategies.

Activity questions:

What is climate change?

What is the impact of climate change on the WASH sector from your local experience?

What adaptation strategies can be implemented to minimize/reduce them?

Activity 2.2: Power point presentation (30 minutes)

This activity will introduce participants to the impact of climate change on WASH facilities especially on

those technologies used for the abstraction of shallow groundwater, and the adaptation strategies to be

taken to reduce/minimize the risk. Ask participants if they have any questions and get their feedback and

reactions to the presentation.

2.1.Climate Change Risk on WASH

Climate Change: According to IPCC definition Climate Change refers to any change in the

climate over time, whether due to natural variability or as a result of human activity.

Water is predicted to be the primary medium through which early climate change impacts will be

felt by people, ecosystems and economies. Both observational records and climate projections

provide strong evidence that freshwater resources are vulnerable, and have the potential to be

strongly impacted by climate change and variability.

Many water supply services rely on groundwater, particularly in rural settings, so developing a better

understanding of climate-groundwater links is vital. The development of groundwater for rural water

supply offers significant advantages (compared to surface water sources) in terms of climate

resilience because of the storage groundwater aquifers offer, specifically, large storage volume

per unit of inflow makes groundwater less sensitive to annual and inter-annual rainfall variation

and longer-term climate change.

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Recharge to groundwater is highly dependent on prevailing climate as well as land cover and

underlying geology. Climate and land cover largely determine rainfall and evapotranspiration,

whereas the underlying soil and geology dictate whether a water surplus (precipitation minus

evapotranspiration) can be transmitted and stored in the subsurface. Groundwater recharge will

also be affected by soil degradation and vegetation changes, both of which may be affected by

climate change and variability, and human activity.

When there is increased intensity of rainfall there is increased risk of flooding, leading to both

infrastructure damage and contamination of surface and groundwater supplies. In rural areas for

example, floods can damage or inundate springs, wells, rainwater harvesting systems and

boreholes, though boreholes are typically less vulnerable. This can hamper both access to water

and cause contamination and health risks. The pit latrines widely used in rural areas are also

vulnerable to flooding and can cause serious environmental contamination, although adapted

designs are available and latrines can be upgraded.

Impact of environmental degradation on WASH sustainability

Degraded micro-watershed has significant impact on the sustainability of the water supply. In the

one hand, degraded micro-watershed has low recharging capacity of the ground leading to

decreased yield of the water point. In the other hand, degraded micro-watershed generate more

flood that may damage the water supply infrastructures and cause contamination of the shallow

groundwater resource. For the detail of this issue, refer section 5 of this ToT manual.

In general table 2.1 below shows the impact of climate change on WASH facilities and the

corresponding adaptation measures.

Table 2.1. Climate change impacts on WASH facilities and adaptation measures

Intense rainfall events - risks and adaptations

Protected Spring Hazard Impact Adaptation: Planning, design Adaptation ongoing

Entry of

contaminated water

from surrounding

area; erosion around

spring box

Public health risk:

Water quality deteriorates –

maybe rapid but short term, or

longer term if wider aquifer

contaminated

Prepare hazard map with community;

address direct threats identified above or

investigate alternative sites/sources

Construct bunds or cut-off drains to divert

runoff away from collection area.

Integrate watershed management activities

with the rural water supply project.

Regularly check and repair

infrastructure.

Monitor & maintain bunds,

drains & other catchment

protection measures

Inundation of spring

– entry of

contaminated

groundwater.

Damage to

infrastructure from



longer term if wider aquifer

contaminated

Implement land management activities in

wider catchment to reduce severity of

floods e.g. terracing, drainage, retention

basis, re-vegetation.

Ensure water collection & storage

infrastructure is properly designed, and

Sanitary inspection.

Implement communication

protocol – advise on safety;

provide support for

household treatment if

necessary.

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land slips and

gullies.

built from durable materials.

Raise awareness of risks from water

quality changes during & after flooding,

and need for household water

treatment/use of safer alternatives.

Develop communication plan: (1) when to

avoid contaminated sources for drinking

during & after floods until water quality is

verified; (2) what are the safe alternatives

(e.g. household treatment, different

sources).

HDWs

Increased

contamination of

groundwater and

lateral flow in soil.

Damage to

infrastructure e.g.

from landslips,

gullies



longer term if surrounding

aquifer contaminated

Prepare hazard map with community;

address direct threats or investigate

alternative sites/sources.

Site well away from latrines and other

sources of groundwater pollution.

Address direct flood risk by building bunds

or cut-off drains to divert runoff.

Implement land management activities in

wider catchment to reduce severity of

floods e.g. terracing, drainage, retention

basis, re-vegetation.

Improve and/or extend well lining to

prevent ingress of contaminated water;

raise well head.

Raise awareness of risks from water

quality changes during & after flooding,

and need for household water

treatment/use of safer alternatives.

Develop communication plan: (1) when to

avoid contaminated sources for drinking

during & after floods until water quality is

verified; (2) what are the safe alternatives

(e.g. household treatment, different

sources).

Seal any abandoned wells to

protect groundwater quality


infrastructure.

Monitor & maintain

protection areas and wider

catchment protection

measures.

Sanitary inspection.

Implement communication

protocol – advise on safety;

provide support for

household treatment if

necessary.

Shock chlorinate well water

after floods have subsided

Dry periods and droughts: Risks and adaptations

Protected springs

Hazard Impact Adaptation: Planning, design Adaptation ongoing

Seasonal or drought-

related reductions in

spring yield, or spring

dries up completely


related reduction in

Seasonal or drought-related

shortages – insufficient

water for demand.

Public health risk from

water rationing/cut-backs,

or use of alternative (unsafe)

Collate secondary information on

geological conditions to understand water

availability & supplement with field

observations.

Discuss seasonal yields of alternative sites

with community – select most reliable


infrastructure.

Monitor & maintain

protection areas and wider

catchment protection

measures.

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water quality – less

dilution of pollutants

sources


deteriorating water quality

at end of dry season or

drought

source(s).

Estimate spring yield and catchment size

needed to meet current and projected

demand.

Increase capacity of collection and storage

facilities.

Raise community awareness about need to

prioritise water use for drinking over other

uses, and/or water rationing at times of

peak demand & low flow.

Investigate management practices that

might increase infiltration and groundwater

recharge – in vicinity of spring and in

wider catchment.

Develop supplementary sources if

necessary to spread risk.

Excavate spring further if

necessary

Monitor water quality during

high risk periods at end of

dry season or drought

HDWs


related reductions in

well yield, or well

dries up completely

Failure of hand pump

as demand increases

and water levels fall


related reduction in

water quality – less

dilution of pollutants

Seasonal or drought-related

shortages – insufficient

water for demand.


water rationing/cut-backs,

or use of alternative (unsafe)

sources


deteriorating water quality

at end of dry season or

drought

Collate secondary information on geological

conditions to understand water availability &

supplement with field observations.

Discuss community experience of well

performance past & present (water quality,

availability) as guide to selecting optimal site.

Estimate well yield and catchment size needed

to meet current and projected demand. If

marginal, investigate alternative sites and

options.

Test yield of well at peak of dry season to

assess resilience.

Raise community awareness about need to

prioritise water use for drinking over other

uses, and/or water rationing at times of peak

demand & low flow.

Investigate management practices that might

increase infiltration and groundwater recharge

– in vicinity of well and in wider catchment.

Develop supplementary sources if necessary

to spread risk.

Regularly check and

repair infrastructure

Focus ‘back stopping’

hand pump maintenance

in dry when mechanical

failure most likely.

Consider deepening wells

if feasible/appropriate

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2.2. Risk screening approaches

Climate risk management describes the process of identifying climate-related risks and

implementing measures to reduce such risks to acceptable levels. Risk assessment has been

defined as ‘…a methodology to determine the nature and extent of risk by analyzing potential

hazards and evaluating existing conditions of vulnerability that could pose a potential threat or

harm to people, property, livelihoods and the environment on which they depend’. Therefore,

both the physical climate hazard, and the vulnerability of the system, is considered under ‘risk’.

Climate risk screening typically avoids probabilistic calculations associated with traditional

(more technical) conceptions of risk assessment. Rather, it involves systematically examining

activities (or projects, programmes, policies, technologies) with the aim of:

Identifying hazards which could potentially cause harm.

Identifying inherent vulnerabilities in the system.

Assessing whether these risks – the product of hazard and vulnerability - are being

taken into account.

Considering the extent to which risks can be reduced or mitigated.

Since the probability of the hazard occurring cannot be reduced, this implies exploring

opportunities for reducing the vulnerability associated with physical hazards. The usefulness of a

risk management approach lies in its emphasis on preventative rather than reactive measures.

Whilst the complete elimination of risk is seldom possible, what is important is identifying the

most significant risks and prioritizing their mitigation

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Section 3: Understanding Water Availability – Tapping Existing Knowledge (Step 1)

Section Overview: This section introduces how to collect existing information on the factors

that are likely to influence the availability and sustainability (and quality) of water for a village

or group of households. This may include geology of the area, performance of existing water

sources, yield of the different water sources. This is the first step in climate and environmental

risk screening processes.

Why this section is important?

Having the knowledge and skill on how to collect existing information on the factors that are

likely to influence the availability and sustainability of water can help the project team assess (a)

what water supply options (e.g. springs, wells, boreholes,...) are likely to be feasible and cost-

effective; and (b) the likely yield and sustainability of water sources. This can save time and

money later on, and means that only those options that are likely to be feasible are discussed with

communities.

Taking the time to tap community knowledge can provide valuable information on which sources

and locations are the most reliable. This information can also be used by the project team, in

partnership with the community, to make informed choices on technical choices and sitting. For

example, older members of the village (particularly women) are likely to know which sources

fail seasonally or in particularly dry years, and may be able to ‘tell the story’ of water

development successes and failures in a village.

Outcome: upon completion of this section, trainees will be able to:

1. Describe the geology of the area to assess resource potential and inform technical choices

(e.g. shallow wells, deeper boreholes, springs).

2. Describe the performance of existing sources over time (yield, reliability, quality) to help

decide on technical choices and sites.

3. Measure the yield of existing sources to see whether they meet regulatory and/or local

needs, and as an input to the catchment sizing process (see section 4).

Activity 3.1: Questioning Participants (10 minutes)

Before fully getting into the substance of the training of this section, the trainer uses this activity

to build anticipation for the content and to gauge how much the trainees knows about the

geology of their respective local area so that the trainer can tailor her/his delivery accordingly.

The trainer start the discussion by asking participants/trainees a few simple questions about the

importance of knowing the local geology, performance of existing sources, and measuring the

yield of the existing sources in selecting technologies, site, and sizing catchment.

Activity 3.2: Power Point Presentation (1hr & 10 minutes)

The trainer will present a power point to the trainees on the topics presented under this section.

This activity will introduce trainees to the importance of understanding local geology,

11

understanding source behavior, and measuring the yield of the existing sources to select

technologies, site, and size catchment. Use this session to clear up any misconceptions on these

three issues. Ask participants if they have any questions and get their feedback and reactions to

the presentation.

Section Contents

Understanding Local Geology

Understanding Source Behavior

Measuring the Yield of the Existing Sources

3.1. Understanding Local Geology (Step 1.1)

Knowing ‘where you are’ in terms of underlying geology is a first step. This can be approached

in two ways: (a) looking at secondary information (e.g. maps, well records) to assess

groundwater potential and likely yields; and (b) follow-up observation in the project area –

looking at rock outcrops and exposed soil/rock profiles – to understand geology and groundwater

condition and potential.

The underlying geology of an area will determine whether water is stored in underground

formations, how much is stored, and the ease with which water can flow to a water point. This

determines the yield of an individual source. Geology can also influence water point choice,

construction, cost and periodic rehabilitation requirements. Storage is the key factor affecting the

resilience of water supplies. Aquifer storage transforms highly variable natural recharge from

rainfall into more stable natural discharge regimes.

Storage is the key factor affecting the resilience of water supplies. Aquifer storage transforms

highly variable natural recharge from rainfall into more stable natural discharge regimes. Storage

is a function of rock porosity. The most porous geologies (e.g. alluvial sediments, highly

weathered hard rocks) can store large volumes of water, so that when recharge from rainfall or

discharge through pumping occurs, changes in water levels are relatively small. However, if the

porosity of the rocks is small (e.g. with mudstones, shales, unweathered hard rocks), changes in

recharge or discharge will have a bigger impact on water levels and a well or spring can dry up.

Please refer Annex 2 for groundwater potential of major African hydro-geological environments.

Hint – when to seek expert advice

If there is no previous experience of well digging or spring development in the project area, the

advice of an experienced geologist should be sought to help decide (a) if well/spring

development is feasible; and (b) well sitting, if well development is feasible.

If previous wells have failed or do not provide water throughout the year, or if there is evidence

of hard rock at shallow depths, alternative options (e.g. a borehole) should be considered.

12

If a large number of wells in a particular area are planned, it may be cost effective to employ a

geologist and possibly geophysical techniques in the sitting of wells, since the increased success

rate may offset the extra cost of hiring a specialist.

Key questions

When the geologist or team of experts are doing site investigation for the rural water supply

project, the following key questions should be answered by the geologist or team experts.

What is the geology of the area? What is their likely groundwater potential?

How might geology vary within the village boundary?

What information or evidence (if any) did previous project teams/drillers leave behind

that might help?

How to get answers for these questions?

Consult a geological map of the area. What sort of rocks are likely to be present?

Visit places where rocks are exposed. River, valleys, cliffs and hills are often good

locations

Look at boulders in the village used for seats, grinding stones etc. Where did they come

from? What kind of rocks?

Visit wells that have been dug previously and examine soil-rock profiles

Encourage people to investigate potential sites themselves e.g. by digging trial pits or

using a shallow auger.

Note that the trainer is expected to assist trainees to exercise being in group on the key questions

indicated above and use the approaches indicated to answer the questions.

Hint - local observation

Field guidance sheets can be used to help the non-expert identify rocks in the field and place

their water scheme in a geological context.

A field guidance sheet can help the user identify rocks at hand specimen scale, at outcrop scale

and regional land setting scale. Photographs and block diagrams can be included as an aid. The

photographs of hand specimens can be used to identify color, texture and mineral composition of

rocks for comparison with field specimens.

At outcrop scale a set of features of rocks (e.g. color, layering, thickness) can be captured in

index photographs. Such photographs can later be used by practitioners in the field as reference.

The same applies to observation of regional geomorphologic setting. Geomorphology is an index

to geology. It is much easier to describe geomorphology (such as dome forming, cliff forming,

undulating, flat laying, plateau, valley forming, dissected, etc) than to name rocks.

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Annex 1 provides an example of a field guidance sheet prepared for project staff in the highlands

of Ethiopia. Similar sheets may already be available in country, or could be developed with the

help of a geologist.

What next?

The information collected above (sub section 3.1 of this section) – from secondary sources

and/or field observation – could be used to draw a rough map of the project area showing

geology, existing water points and springs (functional and non-functional) and likely

groundwater potential. Notes on the performance of existing water points (see table 3.1 below)

could also be added. This will help focus discussion on which areas and source types are likely to

provide the most reliable sources of water. The trainer is expected also to assist trainees prepare

their own map based on the information collected above on their locality. For illustrative

example, see fig 3.1 and 3.2 below. The two figures shows how maps are used as a guide for

water point siting.

14

Fig. 3.1. Figure showing how hydro-geological field notes can be plotted on a geological base map

15

Fig. 3.2. Preliminary groundwater development plan developed from information collected in the field

16

3.2. Understanding Source Behavior (Step 1.2)

Asking communities about the performance of existing sources can provide useful information

on which areas and sources provide the ‘best’ groundwater – the most reliable, as well as the

highest quality and most accessible. This information can be used to inform the selection of new

sites and sources, and/or the rehabilitation of existing ones. Note, however, the danger of projects

simply developing new sources around existing ‘successes’: the result may be good on paper

(another successful well!), but bad for the community (areas where groundwater conditions are

more difficult, but where many people live, are avoided).

The trainer can ask trainees the following questions and get feedback while presenting this sub

section.

What are the main sources of water available for use by the community, or by groups

within it? What sources no longer provide water, and why?

How does water availability vary between sources? Which are the most reliable, and

why?

How does availability from these sources change over time, e.g. across seasons and

between good and bad years?

What other factors affect the use and performance of sources, e.g. mechanical failures,

environmental hazards (flooding, drought, contamination,...) etc?

The following tables can be used to capture information on the type, number and functionality of

existing schemes, and on the reasons for any water supply problems.

Hint – how to get information on source use and behaviour

A good place to begin is with a map, drawn with community members, showing where different water sources

are, what they are used for, and by whom. Notes can be added on the characteristics of these sources. If a

rough geological map was prepared in Step 1.1 above, this can be used as the base.

Notes can be supplemented with more detailed water point histories, best conducted at the water sources

themselves with women, exploring in detail changes in water levels, yields, recovery times, queuing etc. The

aim is to build up a picture of which sources, in which areas, provide (or are likely to provide) the most

reliable groundwater.

17

Table 3.1. Source type, functionality and access

Source type

No.

No. fully functional

schemes

No. schemes

functional part year

(indicate months

when functional)

No. non-

functional

schemes

Access

(Open to all?

Restricted to some?

Only available to

owner?)

Hand-dug well

Drilled well/borehole

Protected Spring

Unprotected Spring

Roof catchment

Open source (e.g. stream)

Other (specify)

Table 3.2. Source problems and their causes

Scheme name and

type

Not enough water

found on

drilling/digging

Collapse of

wall or

sedimentation

Hand pump

failure

Environmenta

l hazard e.g.

flood, erosion,

gullying

Water table

decline;

decline in

spring yield

Other

(specify)

3.3. Measuring the Yield of Existing Sources (step 1.3)

The equipment used and procedure employed to measure the yield of a water sources are

mentioned below.

Equipment needed to measure yield: bucket & stop-watch

Measuring yield: How long does it take to fill a bucket of a known volume?

Example:

If a 10 liter bucket took 8, 10 and 6 seconds to fill at different time, then the average yield of the

water point = (10/8 + 10/10 + 10/6)/3 = (1.25+1+1.67)/3 = 1.3l/sec

Ideally, yield should be measured during the dry season to assess whether the well or spring is

viable (i.e. can meet demand) . The yield has to be measured three times and the average be

taken as the yield of the source. For a well equipped with a pump, information from the community on

18

how much water can be extracted in a 24 hour period may be more valuable than an instantaneous

measure of pump yield.

Table 3.3. Yield of existing water source

Source

Yield (l/sec)

dry season

Yield (l/sec)

wet season

If the yield (in l/sec) for different seasons is not available, ask the following questions: How do

people using this source describe its yield over the year (e.g. fluctuation between dry and wet

season, months when source is dry, etc.)? Use table 3.3 below to measure the yield during the

dry and wet seasons. Is the source producing enough water throughout the year for all users? If

not, where do people get water from during the time when the spring is dry?

What next?

The information collected above will provide an indication of:

Groundwater availability, groundwater quality, groundwater development potential and

the likely cost of developing it (e.g. whether spring sources can be developed, or whether

shallow groundwater can be accessed via wells)

The likely resilience of groundwater resources and sources (based on an understanding or

groundwater storage, and the behaviour of existing sources)

The kinds of sources that may be feasible to develop, or rehabilitate (e.g. do existing

technology types and designs provide reliable water supplies? If not, can they be

developed/rehabilitated to meet target requirements, or do new sources need to be

developed?

Activity 3.4: Group Exercise (1hr & 20 minutes)

Exercises 1.1

1. Describe rock types indicated below (including their hydro-geologic environment) that are most

commonly found in Ethiopia. Describe their implication in water resource potential (average yield) and

technology/scheme selection. For the group exercise, you will have five groups one per region.

a. Basement Rocks

b. Sedimentary Rocks

c. Riverside alluvium

d. Volcanic Rocks

19

Rock type Description of

hydro-geologic

environment

Average yield or

likely

Groundwater

potential

What type of schemes are appropriate for

this type of rocks with that hydro-geologic

environment

Basement Rocks

Sedimentary Rocks

Riverside alluvium

Volcanic Rocks

Other (specify)

2. Based on the information under question number 1 above, and from the performance of one or two

existing water points which you know well in your field experience and having one of the geological

formation mentioned above:

i. Describe the geology of the existing water point in terms of its ground water potential, quality

and reliability.

ii. Describe the water point/points in terms of the type of water scheme/technology constructed; and

quality, quality and reliability of providing water throughout the year.

iii. If nearby community (where the geology is similar to the existing water points) request for the

construction of water point:

a. Which technology type you propose to provide quality, sufficient and reliable water

throughout the year?

b. Describe the likely resilience of groundwater resources (based on an understanding or

groundwater storage, and the behaviour of existing sources) to climate change and

environmental hazards.

Activity 3.3: Group presentations (40 minutes)

Trainees after group work on the above exercise present their work.

Activity 3.4: General Discussion (20 minutes)

The trainer facilitate the general discussion by asking key questions related to the topic covered,

and encouraging trainees to ask question and participate actively.

20

Section 4: Ensuring Sustainability - Estimating Supply and Demand (Step 2)

Section Overview: This is the second step (step 2) of environmental assessment and climate risk

screening). The section focuses on estimating how much groundwater is needed to meet current

and projected needs of the community beneficiaries, and how big does the catchment (recharge)

area of a well or spring need to be provide this water. This section describes how to identify

potential sites for a well or spring that can provide water, at the required yield, on a continuous

basis for domestic needs

Why this section is important?

Working through this section will help WASH staffs identify potential sites for a well or spring

that can provide water, at the required yield, on a continuous basis for domestic needs. Note that

the guidance provided in this section can also be applied to completed projects. In other words,

an understanding of which sites are likely to provide reliable water can also help project staff

identify which existing sites might fail to provide enough water during the dry season, or during

drought. Marginal sites could be targeted for extra monitoring, or could be re-visited to develop

additional ‘back-up’ sources.

Comment – catchment areas for wells and springs

If a well is sited without an adequate catchment area, this increases the risk that it will be dry, or

that dry season yields will be insufficient to meet community needs.

For a spring source, local knowledge is normally used to assess whether dry season flows are

adequate, and so springs will not normally be developed if the catchment area cannot provide

enough water.

In both cases (springs and wells), if catchment areas are marginal in relation to required yield

and demand, then any reduction in recharge, whether from climate variability or catchment

degradation, will put the source under strain.

Outcome of the section: upon completion of this section, trainees will be able to:

employ the basic rules of thumb for selecting site of a water point,

estimate water demand based on the number of households a scheme needs to serve and

their per capita water needs, and

estimate the catchment size needed to meet the water demand.


The trainer, before fully getting into the substance of the training, uses this activity to build

anticipation for the content and to gauge how much the trainees know about the rules of thumbs

for selecting water points, estimating water demands of the community, and estimating the

catchment size so that the trainer can tailor his/her delivery accordingly. The trainer shall start

21

the discussion by asking participants a few simple questions on the rules of thumbs for selecting

water points, estimating water demands of the community, and estimating the catchment size.

The trainers can write the answers on flip chart.

Activity 4.2: Power Point Presentation (3hrs & 20 minutes)

This activity will introduce trainees on rules of thumbs for water point site selection, estimating

water demands of the community, and estimating the catchment size. The trainers shall use this

session to clear up any misconceptions on these three interrelated issues. The trainers shall ask

trainees if they have any question and get their feedback and reactions to the presentation.

To achieve the section objective, the following interrelated three steps (step 2.1 through step 2.3

of this section) should be implemented and followed.

Section content

Selecting sites - rules of thumbs

Estimating water demand

Estimating catchment size

4.1. Selecting sites – rules of thumb (Step 2.1)

Before looking in detail at the catchment size needed to meet demand from a source, it is useful

to look firstly at the topography of the project area – the relief or terrain of the land (the first

rule of thumb).

The importance of drainage

Steep slopes pose a challenge for siting water points. Water within an aquifer will naturally drain to the

lower parts of a catchment. In the worst case, an aquifer may have adequate annual recharge, but be

unable to sustain dry season yields as recharged water drains down slope (See fig 4.1, and table 4.1

below).

For this reason both catchment area and topography (drainage) need to assess the vulnerability of a water

point to change – from climate variation, environmental degradation or changes in population and

demand.

Table 4.1. Importance of topography to avoid rapid drainage

Slope Level of vulnerability

> 20 m drop off within 150 m Highly vulnerable

10 - 20 m drop off within 150 m Vulnerable

5 - 10 m drop off within 150 m Possibly vulnerable

< 5 m drop off within 150 m Adequate

22

Fig 4.1. Estimating the slope to avoid rapid drainage

Fig. 4.2. Scoping the best sites for a water point – the influence of drainage

23

The second important rule of thumbs employed when selecting a water supply site is to consider

contamination risk. Table 4.2 below provides some similar ‘rules of thumb’ for minimizing the

risk of water contamination.

Table 4.2. Minimum Distances from Sources of Pollution

Feature Minimum distance

from water source

Community-level solid waste dump 100m

Storage and dumps of petroleum or pesticides 100m

Slaughterhouses / areas where animals are slaughtered 50m

Toilets / latrines (open pit) 30m

Household waste dump 30m

Stables / kraals 30m

Main road 20m

River / lakes 20m

Laundry place 20m

Dwellings 10m

Source:

Comment – minimizing the risk of contamination

The recommended distances above will not always be possible to achieve. In densely populated

areas, for example, latrines might be closer to water sources than the recommended 30 m. In

such cases, it might be necessary to upgrade latrines from open pit latrines to either sealed pit

latrines or latrines with septic tanks.

24

4.2. Estimating demand (Step 2.2)

To assess the catchment area needed to provide sustainable supply, water demand can be

estimated based on the number of households a scheme needs to serve and their per capita water

needs.

For domestic uses, i.e. drinking, food preparation, personal and domestic hygiene, a figure of 25

litres per capita per day (lcd) is planned for rural Ethiopia during the GTP-II period. This figure

may need to be increased if sources are used for ‘productive’ water uses such as small-scale

irrigation, brewing, brick-making or livestock watering.

Table 4.3. Estimating water needs

Water use

(assuming 5 persons per household, demand = 25lcd for rural Ethiopia during the GTP-II

period)

Households People Daily needs (m3) Annual needs(m3)

20 100 2.50 912.50

50 250 6.25 2,281.25

100 500 12.50 4,562.50

500 2500 62.50 22,812.50

1000 5000 125.00 45,625.00

2500 12500 312.50 114,062.50

5000 25000 625.00 228,125.00

Estimating current water demand

For 50 HHs, the total beneficiary will be 50*5 = 250;

The daily demand is 250 person*25lcd*1m3/1000Litre = 6.25m3

The annual demand/need = 6.25m3*365days/year = 2,281.25m3

Hint – estimating future demand

If to build resilience to carry out the assessment for the current number of households that will

use the well/spring and how the situation might look like in 10 years’ time/in 20 years’ time.

Also consider that a new well/water point might draw in additional people from the vicinity

currently unserved.

Example

Current population: 250 people

Growth rate: 2.5%/year

Population in 10 years’ time: 321

25

Formula used: Nt=N0 x e(rt) where:

Nt = Future population after t years

N0 = Current population

e = Euler’s number = 2.718

r = growth rate (e.g. 0.025)

t = Number of years

Nt = 250*e(0.025*10) = 321

So, estimate the daily and annual demand of the estimated population using the same

water point after 10 years assuming the same 25 lcd.

Daily neeeds = 321 person*25 liter pcd*1m3/1000Litre = 8.03m3

The annual demand/need = 8.03m3*365days/year = 2,929.13m3

4.3. Estimating the Required Catchment Size (wells) or yield (springs) - (Step 2.3)

The catchment area can be used to assess the vulnerability of a water supply system to change

(be it climate variation, environmental degradation, or changes in population and demand). If the

catchment area is sufficiently large the water point should, other factors being equal, be resilient

to climate variability, and have some capacity to satisfy increases in demand. At the other

extreme, catchment areas that are marginal with respect to the required yield are likely to be

more vulnerable to change.

Comment – a simplified water balance

For a system to be sustainable in the long term there must be balance between recharge to the

aquifer, and discharge from the aquifer, whether natural or from pumped abstractions. An

assessment of the catchment water balance for an aquifer, quantifying the sources of recharge,

natural discharges and artificial abstractions (water use and projected demand) is an important

part of water resource management.

A detailed assessment of the water balance of an aquifer in a catchment is complicated, requiring

long term monitoring of rainfall, groundwater recharge, natural discharges (e.g. to base flows in

rivers) and human withdrawals. However, simple methods can give reasonable estimates of the

recharge area (i.e. catchment) needed to meet demand from a source based on rainfall data,

assumptions about how much rainfall recharges groundwater resources, and the required yield

of a source.

As a rule of thumb, and based on evidence from numerous empirical studies across Africa,

recharge can be assumed as 10% of rainfall in areas with over 750mm of rainfall per year. In

areas with less rainfall, the linear relationship between rainfall and recharge breaks down and

recharge is related more to extreme rainfall events than averages.

26

Not all recharged water can be withdrawn from a well, borehole or spring. This is because some

of the ‘10% recharge’ may infiltrate deeper aquifers, discharge laterally to rivers, or evaporate

back into the atmosphere. Recoverable/Extractable recharge may therefore be only 10 - 30% of

the ‘10%’ recharge that infiltrate into the ground water aquifer.

The required catchment area can be calculated as demand (in m3) divided by recharge (in m), or

‘recoverable recharge’.

The table below shows the required catchment area for a source under different demand and

rainfall – recharge assumptions, plus the required spring yields needed to meet different

demands.

Here we assume that the catchment size is likely to be marginal if we base calculations on an

optimistic rainfall-recharge-recoverable groundwater scenario: that recharge is 10% of rainfall,

and all of this (10%) can be captured by a source. Small and adequate catchment area

calculations are based on more cautious assumptions: that recoverable/extractable recharge is

3% and 1% of rainfall, respectively.

Hint – calculating a catchment area for a source in flat terrain

Demand = 50 HH x 5 members x 25 l/day x 365 = 2,281,250 litres per year; 2,281,250 l/year/1000 = 2,281 m3/year

Marginal area: Recharge = 10% of rainfall of 1300 mm = 130 mm; 130mm/1000 = 0.13 m/year

Required catchment area: 2,281m3/year/0.13 = 17,000 m2

Small area: Recharge = 3% of the rainfall of 1300mm= 390mm; 390mm/1000 = 0.039m/year


Adequate area: Recharge = 1% of rainfall of 1300 mm = 13 mm; 13 mm ÷ 1000 = 0.013 m/year


N.B: If the catchment area is less than the marginal area, it is 'Inadequate area'.

27

Table 4.4. Estimating the catchment size and spring yield needed to meet demand

Demand Approx catchment area for well Spring yield

(assuming 5 persons per household, demand =

20 litres/capita per day) (assuming 1300mm average rainfall)

Households Persons

Daily

needs

Annual

needs

Marginal:

Extractable recharge

- 10% of rainfall

Small: Extractable

recharge - 3% of

rainfall

Adequate:

Extractable

recharge - 1% of

rainfall

L / sec

m3 m3 m2 m2 m2

20 100 2.50 912.50 6,700 22,500 67,500 0.03

50 250 6.25 2,281.25 17,000 56,000 168,500 0.07

100 500 12.50 4,562.50 34,000 112,000 337,000 0.14

500 2500 62.50 22,812.50 168,500 561,500 1,685,000 0.69

1000 5000 125.00 45,625.00 337,000 1,123,000 3,369,000 1.39

2500 12500 312.50 114,062.50 842,500 2,808,000 8,423,000 3.47

Hint – interpreting the catchment size table

In Table 4.4 above, the 10% figure gives the required catchment area assuming that 10% of

rainfall infiltrates, and that all of this (100% of the recharge) is available to a water point (an

optimistic assumption – see comment above). Any existing water point that does not satisfy this

criterion is highly vulnerable, and additional sources should be provided. A proposed site that

fails to meet the criterion should only be developed if there are no better options, and as one of a

number of water sources.

The 10% figure indicated in the table 4.3 above assume that 100% of the recharge (10% the

rainfall - 1*0.1*100% = 10%) is available to the well, 3% figure assumes that 30% of the

recharge (0.3*0.1*100% = 3%) is available to a well, and the 1% figure assumes that only 10%

of recharge (0.1*0.1*100% = 1%) is available. These are the extractable recharges. The latter

assumption is much more cautious, and should produce water points that are relatively secure.

Once the rough catchment area in m2 is known, the area itself needs to ‘walked out’ on the

ground. In flat terrain, the catchment can be viewed as a circle around the water source, and the

radius of the circle used to ‘walk out’ distances from the source.

Hint – calculating a catchment area for a source

Demand (in m3)/recharge (in m3)

Example – flat terrain

Demand = 50 HH x 5 members x 25 l/day x 365 = 2,281,250 litres/1000 = 2,281.25 m3/year

28

Extractable Recharge = 10% of rainfall of 1300 mm/year = 130 mm/1000 = 0.13 m/year

Required catchment area: 2,281.25 m3/yr/0.13m/yr = 17,548.08 m2

Approximate square catchment = 132.47 m * 132.47 m

Circular catchment = 74.74 m radius from source

Example – hilly terrain:

From the selected well site, estimate the length in meters of the catchment either estimated

visually or paced out upstream to the ridge line. The width of the catchment is estimated by

taking the distance between ridge lines, or alternatively half the distance between the valleys or

stream lines on either side of the well under investigation. The catchment area is the two

measurements multiplied – fig 4.3, and example below.

Fig 4.3. Width and Length of a catchment to calculate the size of a catchment

To decide whether it is worth developing a spring, a simple assessment is made comparing yield

with demand, based on the population served, or likely to be served in future. As a precaution,

the yield of the spring during the driest period of the year is used for the calculation.

29

Hint - comparing spring yield to demand

To assess whether the yield of a spring is sufficient to meet demand, calculate the total water

demand of the population to be served annually and compare this to yield. The calculation of

total yield should be done based on the lowest yield as measured during the dry season.

Demand: Number of Households*number of household members*25 l water per day per

capita*365

Yield: spring yield (l/sec)*60sec/min*60min/hr*24hrs/day*365days/year

Example:

Demand: 50 households*5 members*25 l per day*365 days = 2,281,250 l/year (2,281 m3/year)

Yield: Yield during driest period: 1.25 l/sec*60 sec*60 min* 24 hours*365 days = 39,420,000

l/year (39,420 m3 / year). The yield of the spring is safe in terms of providing what is demanded.

The calculations above may appear daunting for some users. For this reason, they have been

embedded in the ‘look up’ graphs below (Figure 4.4). These allow users to find the catchment

areas needed to meet demand for different numbers of households under different rainfall-

recharge scenarios. Alternatively, they can be used to see if an existing well is likely to have a

marginal, small or adequate catchment area.

For an existing well, select the graph closest to the mean annual rainfall for the community.

Using measured or estimated catchment areas, plot the area on the vertical axis against the

number of households served by the well. If the site plots in the red zone at the bottom of the

graph, the well has an inadequate catchment for current demands. In the orange, marginal

catchment zone, wells are likely to be very vulnerable to seasonal variation in rainfall. In the

yellow area catchments are still small and vulnerable to environmental change. If a well is in the

green zone this suggests it has an adequate catchment area, although its performance will depend

on local aquifer properties and topography.

For a proposed well, the graph should be read upwards from the number of households to find

areas associated with adequate, small and marginal catchments. Other factors being equal a site

with an adequate catchment will be preferred. If the communities’ preferred sites have a

marginal catchment, the risk of seasonal well failure should be explained before commencement

of excavation.

Although primarily designed to assess shallow dug well catchments, the same graphs can be used

to assess the security of spring sources. If dry season flow measurements suggest a spring is

marginally able to support the desired number of households, a catchment area calculation can

suggest whether the spring is likely to be vulnerable to low flow in particularly dry years.

30

Fig 4.4. Catchment sizing for different rainfall, recharge and demand scenarios

31

Hint – sustainability risks for existing water points

The approach outlined above can also be used to assess whether existing water points are

vulnerable in terms of their topography-drainage and catchment characteristics.

Project staff may already have an informed opinion about which sources might be vulnerable.

They can apply the tools above to check/confirm and, if necessary, consider developing

additional water sources that would help spread risk.

Activity 4.4: Group Exercise (3hrs)

Exercise 4.1. (30 minutes)

1. Discuss how topography and catchment area/size influence the vulnerability of water points to

climate variations, and environmental degradation or change in population and demand. How

were you managing this when you were planning and implementing rural water supply?

2. Discuss the experience that you have when sitting water points to protect the water points

from contamination (please do against the rule of thumbs mentioned in this module if you know

them before; or what precaution measures you were taking). Did you consider the environmental

health aspects of the rural water supply to ensure the water is safe?

32

Exercise 4.2 (2hr & 30 minutes

1. Do you estimate the population of a particular rural community when planning to construct a

water point so that the water point will be resilient to the increased water demand due to

population growth? For what years you predict most commonly? Which prediction formula you

use? Using the following information/data and population prediction formula:

i. Calculate the daily and annual needs (m3) of the community; and estimate the catchment size for

the 10%, 3% and 1% extractable recharge, and comments catchment size for each case. Use

1000mm rainfall data of the area.

ii. Predict the population after 10 years

Nt=N0 x e(rt) where:

Nt = Future population after t years

N0 = Current population

e = Euler’s number = 2.718

Current household who requested water point construction are 70, and assuming 5

persons per household, demand = 25lcd. the population growth rate is 2.5% (e.g. 0.025)

iii. For the estimated population under question #ii above;

a. Estimate the daily and annual needs (m3) of water after 10 years

b. size the catchment (for spring and well separately) for the predicted population assuming that

the extractable/recoverable recharge is 10%, 3% and 1%. The average annual rainfall of the

area under consideration be 1000mm. What will happen when the catchment area is 75,000m2

for the recoverable recharge of 3%? Can the water point provide sufficient and reliable water

throughout the year?

c. Calculate the yield of the spring if spring is the selected technology?

d. Do you plan the water point with the current population or for the predicted one?

These exercise will also help trainees for the Woreda training which they are going to give for

the Woreda people.

Activity 4.5: Group presentations (1hr & 10 minutes)



The trainer facilitate the general discussion by asking key questions, and encouraging trainees to

ask question and participate actively.

33

Section 5: Protecting Sites and Sources – Hazard Assessment and Mitigation (Step 3)

Section overview: This section focuses on how to assess the direct environmental hazards to the

water point, and the indirect environmental degradation processes in the catchment. The

importance of doing this is also discussed in the section. The section also describes how to

identify measures to address direct and indirect hazards via a catchment protection plan

Why the section is important?

Besides the impacts of well construction and spring protection on the environment (e.g. cutting

trees, temporary water pollution, improper disposal of dug out sub-soil), a well-protected and

managed environment is crucial for the sustainability and functioning of water points. This is

because:

Direct environmental hazards, such as expanding gullies, floods and landslides can

damage water points directly.

There are indirect environmental aspects to consider as well, relating to degradation

processes within the broader catchment that can affect the sustainability of a water

system.

Ultimately, the sustainability and resilience of a water system is influenced by how well a

catchment of a water source can absorb rainfall through infiltration - water that will eventually

feed into the (shallow) groundwater on which the water system depends.

Outcome of the section: upon completion of this section, trainees will be able to:

o Assess direct environmental and climate change hazards to the water point,

o Assess indirect environmental degradation processes in the catchment, and

o Identify measures to address direct and indirect hazards via a catchment protection plan.


The trainer, before fully getting into the substance of the training, uses this activity to build

anticipation for the content and to gauge how much the trainees know about the direct and

indirect environmental and climate change hazards that may result near the water points and

general catchment, and developing catchment protection plan including monitoring plan to

mitigate the hazards identified so that the trainer can tailor his/her delivery accordingly.

The trainer shall start the discussion by asking participants a few simple questions on their

knowledge and experience on the direct and indirect environmental and climate change hazards

that may result near the water points and general catchment, and on how to develop catchment

protection plan including monitoring plan to mitigate the hazards identified. The trainers shall

write the answers on flip chart.

34

Activity 5.2: Power Point Presentation (1hr & 50 minutes)

This activity will introduce trainees on the direct and indirect environmental and climate change

related hazards that may result near the water points and general catchment, and developing

catchment protection plan including monitoring plan to mitigate the hazards identified. The

trainers shall use this session to clear up any misconceptions on these issues. The trainers shall

ask trainees if they have any questions and get their feedback and reactions to the presentation.

Contents of the Section

Assessing Direct Hazards Near a Water Point

Assessing Indirect Environmental Hazards in the Wider Catchment

Developing a Catchment Protection Plan

Once a site has been identified (section 3 and 4 of this training manual), direct and indirect

environmental and climate change hazards should be assessed. If there are direct hazards in the

vicinity of the proposed water point (section 5.1), these need to be addressed. If that is not

possible – because of the size of the hazard or the lack of financial or technical capacity –

alternative sites may need to be considered.

Figure 5.1 below summarizes the decision-making process in relation to site selection. Once a

final site has been identified, indirect environmental and climate change hazards in the wider

catchment of the water source should be identified (section 5.2) and addressed (section 5.3).

Fig. 5.1. Integrating environmental risk assessment in water point sitting

35

5.1 Assessing direct hazards near a water point (Step 3.1)

The first step in assessing the environmental hazards and identification of mitigation measure is

assessing direct hazards near a water point. A good place to start is with a map of the vicinity of

the water point (approx. 150 m radius), whether planned or an existing source – showing the

main hazards and degradation features. These may include gullies, areas affected by flooding,

landslips or areas prone to landslides. Pollution risks can also be included, such as latrines and

waste dumps (see Table 5.2).

Degradation features that might not pose an immediate threat to the water point but left untreated

might be a hazard in future (e.g. rills, cattle tracks developing into a gully, etc.) can also be

included.

Fig 5.2. Environmental hazards that might affect a water source

In order to decide whether to go ahead or not with the final site selection, direct environmental

threats should be assessed for their severity. If they are so severe that they cannot be resolved

within reasonable limits, it might be better to identify alternative sites.

36

i. Gullies

The existence of gullies in an area do have a multitude of impacts in the rural water supply

system including, but not limited to:

Local lowering of the water table (gullies suck water from springs, dug-wells and hand

pumps, because by lying below they have an effect of negative pressure)

Damage to infrastructures such water supply schemes

Figure 5.3 shows active and deep gully that may pose serious damage to the water point both

infrastructure damage and lowering of water table.

Fig. 5.3. Picture showing active and deep gully

Table 5.1 below provide a simple ‘traffic light’ system to identify whether gullies might pose a

major threat to water points.

Table 5.1. Assessing the risk posed by gullies to water points

Dimension (length x width x

depth = m3)

Low

0-10m3 11-25m3 >25m3

Number of

gullies in

vicinity of

water

point

1 (C) (B)

2-3 (C) (B) (A)

Hig

h

4 or

more (B) (A)

Example: length (25m) x width (2m) x depth (0.5m) = 25 m3

37

Hint – what to do about gullies

If there is a gully or gullies in the vicinity of a water point, they need to be treated – i.e. if in a

yellow-shaded cell.

Consider identifying alternative locations for a water point if you identify several and or

significant gullies – i.e. in a red-shaded cell.

In both cases, consult natural resource management experts or relevant guidelines for how to do

this.

If a gully of a given dimension and/or frequency is located down slope of the water point it is

often posing a more serious threat to the water point than if the gully is located elsewhere. In that

case, consider relocating the water point and initiate gully rehabilitation measures.

If a gully of the dimension/frequency labelled ‘A’ in Table 5.1 above is in the down slope

area of the water point, classify as highest (‘severe’) threat level.

If a gully of the dimension/frequency labelled ‘B’ in Table 5.1 is in the down slope area of

the water point, classify as second highest (‘high’) threat level.

If a gully of the dimension/frequency labelled ‘C’ in Table 5.1 is in the down slope area of

the water point, classify as third highest (‘moderate’) threat level.

ii. Area affected by flooding

Regular flooding

If the area where a water point is to be constructed and its immediate environment (e.g. within a

radius around the site of the water point of 150 m) is regularly flooded (e.g. during the rainy

season) then consider the following actions:

o Relocate the site of the water point away from flood prone areas

o Raise the well head and seal the well to prevent any polluted flood water from entering

the well

o Manage water flows through cut-off drains, artificial water ways and levees

o Ensure areas from where floodwater originates is open-defecation free and free from

other pollutants

o If water point is not accessible during periods of flooding, ensure alternative protected

water sources are available

Periodic flooding

o Raise the well head and seal the well to prevent polluted water from entering the well.

38

Hint – thinking about extremes

Also consider flooding that might happen less frequently (e.g. every 5 years, every 10 years)

during very heavy rainfall events that might affect a large area and/or create a lot of damage.

Consider measures that might reduce the impacts of such extreme events.

iii. Landslides/slips

Landslips may occur because of a variety of natural (geological and morphological structures,

such as weak or weathered material, differences in permeability of material) and human causes

(deforestation, cultivation of steep slopes, road construction). Often they are found on steep

hillsides where vegetation is disturbed, for example along a foot path or where rills have

developed as a result of uncontrolled runoff. Landslips can also develop around springs because

springs often appear at the intersection of different rock formations

Landslips need to be treated otherwise there is a danger that they expand and result in more

severe damage to a water point.

Fig 5.4. Landslips/landslides

39

5.2. Assessing Indirect Environmental Hazards in the Wider Catchment (step 3.2)

Once a potential site for a water point has been identified and deemed safe, i.e. not threatened by

environmental and climate change hazards, potential indirect environmental hazards should be

identified in the wider catchment of the water point. This is important as natural resource

degradation in the wider catchment can affect the risk of flooding, and gullying that might draw

down local water tables.

Changes in land use and land degradation can also have longer term impacts on groundwater

conditions by affecting local water balances. Making predictions is difficult, however, because

recharge to groundwater is strongly influenced by prevailing climate, as well as land cover and

underlying geology (see below).

As a first step, a base map of the catchment of the water point should be drawn, main land cover

units mapped and major degradation features identified. An example is provided in fig. 5.5

below, and in three-dimensional form in Figure 5.6.

Comment – catchment protection and groundwater recharge

Recharge to groundwater is highly dependent on prevailing climate, as well as land cover and underlying

geology. Climate and land cover largely determine rainfall and evapotranspiration, whereas the underlying

soil and geology dictate whether a water surplus (precipitation minus evapotranspiration) can be transmitted

and stored in the sub-surface.

Land use change can have a very significant impact on groundwater recharge, and outcomes can be

counterintuitive. For example, it is often assumed that planting trees and ‘re-vegetating’ catchments will

increase groundwater recharge and availability. In practice the reverse can be true, because trees and

perennial native vegetation can draw up and evaporate a lot more water than grass or crop land. So a

decrease in runoff and greater soil moisture retention can still translate into less groundwater recharge if

plants end up using more water.

40

Fig 5.5. Topographic base map showing areas of environmnetal degradation and initial identification of causes

Very steep slope, high soil

erosion rate despite

terracing

Deep gully, expansion

further up-slope

Badland – expansion into

crop land

Medium steep slope, high

soil erosion (sheet erosion

and deep rills)

High runoff from village

area because of compacted

soil

Cattle tracks – might

develop into gully

Heavily grazed, soil

compaction

Flooding – run-on from

foot path - sediment

deposition on grazing land

Water way without any

protection – can develop

into gully

41

Fig 5.6. Similar base map including major areas of environmental degradation and initial identifications of causes

Hint – accounting for gender

Involve both men and women in drawing the catchment map – this might identify special

features particularly important for either men or women – for example, accessing water points on

a steep slope might be more of an issue for women if they are mainly responsible for collecting

water. Or certain areas may be used for defacation by different groups.

Cropland covered by

sediments washed down

from bare grazing area

Overgrazing, high runoff,

deep cattle tracks, bare

patches of soil visible

Mountain tops

completely cleared of

forests -> high rates of

runoff

Unprotected

drainage canal –

danger of deep

gully formation

Heavily grazed, soil

compaction

42

Table 5.2. Examples of degradation features and possible reasons

Degradation

feature

Location Possible Reason

Gully on grazing land Overgrazing, Cattle tracks

on crop land Traditional furrows to drain excess water

Ploughing up & down the slope

Absence of constructing cut off drain

above the crop land

on bush/forest land Bush/forest clearing

as a result of foot path/sealed

area/cattle track

Alignment, lacking maintenance

Sheet & rill erosion on crop land land management practices

Flooding on grazing land/on crop land Inappropriate drainage

Insufficient water infiltration

Land slips On steep crop & grazing land Land management practices

Land slides Along rivers, Around springs,

On steep slopes

Deforestation

An assessment of the severity of indirect hazards can also be carried out. This can help establish

priorities for action – see Table 5.3 below.

Table 5.3. Assessing the severity of degradation features

Description of degradation features Severity/extent of degradation Comments

none Low medium high

Sheet/splash erosion on crop land

Rills1 on crop land

Gullies2 on crop land

Gullies on grazing land

Gullies on degraded land

Gullies in forest land

Sediment deposition

Cattle step

Land slip/land slide

Riverbank erosion

Deforestation

1 Rills = can be smoothed out completely by normal land management / cultivation practices. 2 Gully = larger than rills and can no longer be smoothed by normal cultivation practices, persistent.

43

NB: Gullies or landslips identified in this step are gullies/landslips in the catchment/watershed

area and are not a direct threat to the water point. Nevertheless, such environmental degradation

features in the catchment/watershed need to be addressed as well.

5.3 Developing a Catchment Protection Plan (Step 3.3)

Using the base map drawn in step 3.2 showing the main indirect hazards and areas where

degradation processes are ongoing (see Table 5.2 and 5.3), identify appropriate mitigation

measures.

For all degradation processes classified as medium or high seek collaboration with relevant

authorities (office of agriculture) or partners with expertise in natural resource management to

identify the most appropriate conservation technology. Table 5.4 below provides some examples

of corrective measures depending on the degradation feature and its location. It also provides

some ideas what the underlying causes of the degradation feature might be which should be

addressed as well.

Table 5.4. Possible corrective measures for main degradation features

Degradation

feature

Location Cause Correction

Gullies Grazing land Overgrazing

Cattle tracks

Absence of cut-off drain above

the grazing land

Check-dam

Fencing

Re-vegetation of gully & surrounding

areas

Construction of cut-off drain

Crop land Traditional furrows to drain

excess water

Absence of cut-off drain above

the crop land

Ploughing up & down the slope

Ploughing along the contours

Cut-off drain & area closures above crop

land to reduce run-on & increase

infiltration

Terracing

Check-dam

Bush/Forest land Bush/forest clearing o Area closure

o Cut &carry

As a result of foot

path/sealed area/cattle

track

Alignment

Inefficient maintenance

Re-alignment

Cut-off drains

Stone paving and check structures

Sheet & rill

erosion

Crop land Land management practices Land management practices (e.g. contour

ploughing, increasing organic matter

content of the soil)

Soil & stone bunds

Artificial water ways

Cut-off drains above crop land

Flooding Grazing land/Crop land Inappropriate drainage

Insufficient water infiltration

o Artificial water ways

o Cut-off drains

o Soil and/or Stone bunds on crop land to

enhance water retention and infiltration

o Area closures/afforestation on hill tops /

steep slopes

44

Degradation

feature

Location Cause Correction

Land slips Steep crop & grazing land Land management practices

Landslides Along rivers

Around springs

Deforestation

o Area closure

o Afforestation

o Retention walls

o Fencing to avoid damage from livestock

Once the main degradation features and corrective measures have been identified and drawn on

the base map (Figure 5.7), a catchment protection plan should be elaborated and agreed by all

relevant stakeholders. Such a plan should include where which corrective measure is best suited,

how much resources (labour, finance, in kind and other) are needed, who should provide the

resources, who provide technical support including monitoring, and what additional material

might be required.

In addition to the catchment protection plan, monitoring plan should be prepared that include the

objective of monitoring, the parameters/indicators to be monitored, who and when to monitor,

frequency of monitoring and the resources required to monitor.

Fig. 5.7. Base map showing measures to address catchment degradation

45

Activity 5.3: Group Exercise (1hr& 30 minutes)

Group exercise 5.1

1. Why is important to consider the direct and indirect environmental hazards when planning

and implementing rural water supply? What are the implication not considering them?

Answer separately for direct and indirect environmental hazards.

2. Discuss how you were managing the environmental hazards (both direct and indirect) when

planning and implementing rural water supply schemes. Which environmental hazards were

major problem in your localities? With which organizations you are working to manage

these hazards?

3. Have you been considering the impact of climate change when planning and implementing

rural water supply? Discuss how.

4. Take one micro-watershed in your locality that may have a number of water points within the

micro-watershed. Prepare a base map and Identify major direct and indirect hazards, and

develop mitigation measure to avoid or minimize the impacts/hazards. Develop catchment

development plan, and monitoring plan for it.

This will help trainees for the Woreda training which they are going to give for the Woreda

people.

Activity 5.4: Group presentations (40 minutes)



The trainer facilitate the general discussion by asking key questions on the topics covered in this

section, and encouraging trainees to ask question and participate actively.

46

Section 6: Record Keeping

Section Overview: This section focuses on what, why and where to record, store and make

available all relevant records of water points.

Outcome of the section: upon completion of this module, trainees will be able to understand

what, why and where data should be kept.


The trainers, before fully getting into the substance of the training, uses this activity to build

anticipation for the content and to gauge how much the trainees knows about the on recording,

storing and making available all relevant records of water points so that the trainer can tailor

his/her delivery accordingly. The trainer shall start the discussion by asking participants a few

simple questions on their knowledge and experience on recording, storing and making available

all relevant records of water points. The trainers shall write the answers on flip chart.

Activity 6.2: Power Point Presentation (40 minutes)

This activity will introduce trainees on recording, storing and making available all relevant

records of water points. The trainers shall use this session to clear up any misconceptions on

these issues. The trainers shall ask trainees if they have any questions and get their feedback and

reactions to the presentation. Handout should be distributed to the trainees before the

presentation.

Content of the Section

o What data should be kept?

o Why should data be kept?

o Where should the data be kept?

What data should be kept?

o Geological field notes from reconnaissance trips

o Data from geophysical surveys (if any were carried out)

o The digging or drilling report (log), including all data relating to the drilling,

construction and geological/geophysical logging, including all dry holes

o Data and results from pumping tests

o Water level (using a dipper, if required) across different season

o Number of people using the scheme and estimate of amount collected per

person/household across different seasons

o Any incident when water supply system was not functional, reasons and actions

undertaken

o Any incident when water supply system was damaged as a result of direct

environmental hazards and actions undertake to fix the damage

o Any chemical, biological and physical parameters from water testing.

47

Why should data be kept?

This kind of information is helpful in building a picture of the hydrogeology of an area and can

help better inform future water scheme developments. For example, it may help governments to

develop planning tools, it may help the district hydro-geologist to increase his/her understanding

of the groundwater occurrence in the area and it can help implementing partners in their

decisions to develop further water schemes.

Where should the data be kept?

Collected data should be kept at local level and a copy should be made available to local and

district authorities (e.g. at the office of the district water authority) and to implementing partners.

Hint – drilling logs

A drilling log is a written record of the soil layers and/or geological formations found at different

depths. Soil/rock samples should be taken at regular depths (e.g. every meter) and described

during the drilling or digging process. The soil/rock description is then recorded in the form of a

drilling log. The drilling log will help to determine:

The right aquifer for installation of the well-screen

Depth and length of the well-screen

Depth and thickness of the gravel pack

Location of the sanitary seal


The trainer facilitate the general discussion by asking key questions, and encouraging trainees to

ask question and participate actively. The discussion may focuses on the experiences of training

on managing records (what, why, and where aspects of keeping records).

48

Field Exercise (1day)

On the fourth day of the ToT in the afternoon, a half day field trip will be organized for the

trainees exercise on all aspects of the issues covered by ToT manual with the objective of

making the training practical. On the fifth day of the training, in the morning, trainees being in

their respective groups will prepare power point presentation. On the same day in the afternoon,

they will present their group exercise, and will have discussion based on the presentations.

1. Place of the field exercise

Since the ToT will be organized in Bahir Dar, the site will be most probably in Farta Woreda

Woreda. The site will be selected in consultation with Amhara region RSU. It will be selected

latest mid October 2015. The site to be selected need to have at least one water point (two

preferable). WASHCO members are important to be there as the trainees may ask them questions

regarding the performance of the water points, history of the water point, challenges, and other

related issues. Woreda CMP supervisor also important to be there to give some information.

2. Objective of the field visit

The objective the field visit and exercise is to enable the trainees practice what they have

acquired in theory so that it will help them to prepare them to cascade the ToT to Zone and

Woreda trainees later on.

3. Group work on the field exercise (3hrs & 30 minutes)

Issues/focus area to be covered by the field visit

The trainees, after having the field visit, will work on the following:

i. Describe the geology of the site and its implication on ground water potential, and

appropriate technology.

ii. Comment on the type of existing water scheme in relation to the hydro-geologic

environment of the site. Is the existing water scheme appropriate? If not why? If yes,

why?

iii. Describe the vulnerability of the water resource of that particular site to climate change

and environmental hazard.

iv. Ask the yield of the water point during the driest period. And then, based on the annual

rainfall data of the site/area and the total beneficiary of the water point (for both current

and design), size the catchment. Is the catchment of the existing water point sufficient

assuming that the recoverable recharge to the aquifer is 10%, 3% and 1% of the annual

rainfall.

49

v. Draw a base map of the catchment of the water point consisting of main land use type,

major environmental hazards (both direct and indirect), and possible reasons for the

hazards.

vi. Rate the severity of the environmental hazards observed using the table below

Description of environmental

hazards

Severity/extent of hazards Comments

none Low medium high

vii. Prepare catchment development plan (with separate development map).

Environmental

hazards

Location Cause Correction/mitigation measures

viii. Develop a monitoring plan for the catchment development plan.

4. Group presentations (2hrs)

Presentation content

Two groups will present the observation of their field exercise. The group presentation will have

the following content.

A. General description of the site (Woreda, Kebele, site, type of water scheme, beneficiary

number - Male & Female).

B. General condition of the water point (functionality, protection of the water point -

fencing, catchment protection, ...)

C. The answers of the field exercise questions indicated under #3 above of this field

exercise.

50

Reference

1. Easter Nile Subsidiary Action Program (ENSAP), 2012. A field guide on gully prevention

and control, Addis Ababa, Ethiopia.

2. Roger Calow, Eva Ludi, Andrew McKenzie, Seifu Kebede (2015). Climate Risk Screening

for rural water supply in Ethiopia, a guidance note for program staffs, Addis Ababa, Ethiopia.

51

Annex 1: A field guidance sheet that can help the user identify rocks and their water resource potential

55

Annex 2: Groundwater potential of major African hydro-geological environments

Hydrogeological

sub-environment

GW potential &

average yields

Groundwater targets C

ryst

all

ine

ba

sem

ent

rock

s

Highly weathered

and/or fractured

basement

Moderate

0.1- 1 l/s

Fractures at the base of the deep weathered zone.

Sub -vertical fracture zones.

Poorly weathered or

sparsely fractured

basement

Low

0.1 l/s – 1 /s

Widely spaced fractures and localised pockets of

deep weathering.

Co

nso

lid

ate

d s

edim

enta

ry r

ock

s

Sandstone Moderate – High

1 – 20 l/s

Coarse porous or fractured sandstone.

Mudstone and shale Low

0 – 0.5 l/s

Hard fractured mudstones

Igneous intrusions or thin limestone / sandstone

layers.

Limestones Moderate – high

1-100 l/s

Fractures and solution enhanced fractures (dry

valleys)

Recent Coastal and

Calcareous Island

formations

High

10 – 100 l/s

Proximity of saline water limits depth of boreholes

or galleries. High permeability results in water

table being only slightly above sea level

Un

con

soli

da

ted

sed

imen

ts

Major alluvial and

coastal basins

High

1 – 40 l/s

Sand and gravel layers

Small dispersed

deposits, such as

river valley

alluvium and coastal

dunes deposits

Moderate

1 – 20 l/s

Thicker, well-sorted sandy/gravel deposits.

Coastal aquifers need to be managed to control

saline intrusion.

Loess Low – Moderate

0.1 – 1 l/s

Areas where the loess is thick and saturated, or

drains down to a more permeable receiving bed

Valley deposits in

mountain areas

Moderate – High

1 – 10 l/s

Stable areas of sand and gravel; river-reworked

volcanic rocks; blocky lava flows

Vo

lca

nic

Ro

cks

Extensive volcanic

terrains

Low - High

Lavas 0.1 – 100 l/s

Ashes and

pyroclastic rocks

0.5-5 l/s

Generally little porosity or permeability within the

lava flows, but the edges and flow tops/bottom can

be rubbly and fractured; flow tubes can also be

fractured.

Ashes are generally poorly permeable but have high

storage and can drain water into underlying layers.

the federal democratic republic of ethiopia ministry of

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